Method for making smooth transitions between differing lead segments

Abstract

A method for forming a lead body includes contacting a proximal section of the lead body having a lumen and a first lead body characteristic to a distal section of the lead body having a lumen and a second lead body characteristic. The proximal and distal sections are contacted such that their lumens are axially aligned. A lap band is disposed about a portion of the proximal section and a portion of the distal section, and is thermally formed to the proximal and distal sections. Axially compressive pressure is applied to the lap band as the lead body is being thermally formed. The pressure applied is sufficient to result in the lead body having an outer diameter in regions proximally and distally adjacent to the lap band that are substantially the same to an outer diameter in a region formed by the lap band.

What is claimed is: 
     
         1 . A method for forming a lead body having a transition from a first section to a second section, the method comprising:
 contacting (i) a proximal portion of the second section of the lead body to (ii) a distal portion of the first section of the lead body, wherein the proximal portion of the second section of the lead body defines a lumen, wherein the distal portion of the first section of the lead body defines a lumen, and wherein the proximal portion of the second section is contacted with the distal portion of the first section such that the lumen of the proximal portion of the second section is axially aligned with the lumen of the distal portion of the first section;   disposing a lap band about at least a portion of the proximal portion of the second section and at least a portion of the distal portion of the first section;   thermally forming the lead body by bonding the lap band to the proximal portion of the second section and the distal portion of the first section; and   applying axially compressive pressure to the lap band as the lead body is being thermally formed, wherein the pressure applied is sufficient to result in the lead body having an outer diameter in regions proximally and distally adjacent to the lap band that are substantially the same to an outer diameter in a region formed by the lap band.   
     
     
         2 . The method of  claim 1 , wherein contacting the proximal portion of the second section to the distal portion of the first section such that the lumen of the proximal portion of the second section is axially aligned with the lumen of the distal portion of the first section comprises disposing the proximal portion of the second section and the distal portion of the first section about a mandrel, wherein the mandrel axially aligns the lumen of the proximal portion of the second section and the lumen of the distal portion of the first section. 
     
     
         3 . The method of  claim 2 , wherein the mandrel has an outer diametric dimension substantially the same as the inner diametric dimension of the lumens of the proximal portion of the first section and distal portion of the second section. 
     
     
         4 . The method of  claim 1 , wherein the second section of the lead body has a substantially uniform inner diameter, and has a first outer diameter along a length from a proximal end to a location distal to the proximal end, and has a second outer diameter distal to the location distal to the proximal end, wherein the first outer diameter is smaller than the second outer diameter. 
     
     
         5 . The method of  claim 4 , wherein contacting the proximal portion of the second section to the distal portion of the first section such that the lumen of the proximal portion of the second section is axially aligned with the lumen of the distal portion of the first section comprises disposing at least a portion of the distal portion of the first section about at least a portion of the proximal portion of the second section having the first outer diameter. 
     
     
         6 . The method of  claim 4 , wherein the proximal portion of the second section of the lead body has a thickness and wherein half the difference in the second outer diameter and the first outer diameter of the second section of the lead body is substantially the same as the thickness of the distal portion of the first section. 
     
     
         7 . The method of  claim 1 , wherein the first section of the lead body has a substantially uniform inner diameter, has a first outer diameter along a length from a distal end to a location proximal the distal end, and has a second outer diameter proximal to the location proximal the distal end, wherein the first outer diameter is smaller than the second outer diameter. 
     
     
         8 . The method of  claim 7 , wherein contacting the proximal portion of the second section to the distal portion of the first section such that the lumen of the proximal portion of the second section is axially aligned with the lumen of the distal portion of the first section comprises disposing at least a proximal portion of the second section about at least a portion of the first section having the first outer diameter. 
     
     
         9 . The method of  claim 8 , wherein the distal portion of the second section of the lead body has a thickness and wherein the thickness of the proximal portion of the second section is about half the difference of the second outer diameter and the first outer diameter of the first section. 
     
     
         10 . A method for forming a lead body, the method comprising:
 providing a distal section of the lead body having a substantially uniform inner diameter, a first outer diameter along a first length from a proximal end to a first location distal the proximal end, and a second outer diameter distal the first length, wherein the first outer diameter is smaller than the second outer diameter,   wherein a lumen extends through the distal section of the lead body from the proximal end of the distal section to a distal end of the distal section;   providing a proximal section of the lead body having a substantially uniform inner diameter, a first outer diameter along a first length from a distal end to a first location proximal the distal end, and a second outer diameter proximal the location proximal the distal end, wherein the first outer diameter is smaller than the second outer diameter,   wherein a lumen extends through the proximal section of the lead body from the distal end of the proximal section to a proximal end of the proximal section;   contacting the proximal section to the distal section such that the lumen of the proximal section is axially aligned with the lumen of the distal section;   disposing a lap band about a portion of the proximal section and a portion of the distal section;   bonding the lap band to the proximal and distal sections.   
     
     
         11 . The method of  claim 10 , wherein contacting the proximal section to the distal section comprises contacting the distal end of the proximal section to the proximal end of the distal section. 
     
     
         12 . The method of  claim 11 , wherein the lap band has a thickness,
 wherein the first outer diameter of the proximal section is substantially the same as the first outer diameter of the distal section,   wherein the second outer diameter of the proximal section is substantially the same as the second outer diameter of the distal section,   wherein the thickness of the lap band is about half the difference of the second outer diameter of the proximal section and the first outer diameter of the proximal section, and   wherein forming the lead body comprises forming a lead body having a substantially uniform outer diameter from a location proximal the lap band region to a location distal the lap band region.   
     
     
         13 . The method of  claim 10 , wherein the distal section of the lead includes a second length from the first location to a second location distal the first location, wherein the outer diameter of the second length is the second outer diameter of the distal section and wherein the distal section has a third outer diameter distal the second location, wherein the third outer diameter is greater than the second outer diameter. 
     
     
         14 . The method of  claim 13 , wherein contacting the proximal section to distal section comprises disposing at least a distal portion of the proximal section about at least a portion of the first length of the distal section. 
     
     
         15 . The method of  claim 14 , wherein the inner diameter of the proximal section is substantially the same as the outer diameter of the distal section along the first length, wherein the first outer diameter of the proximal section is substantially the same as the second outer diameter of the distal section, wherein the second outer diameter of the proximal section is substantially the same as the third outer diameter of the distal section, wherein the lap band has a thickness that is about half the difference between the second outer diameter of the proximal section and the first outer diameter of the proximal section, and
 wherein disposing the lap band about a portion of the proximal section and a portion of the distal section comprises disposing the lap band about the first length of the proximal section and the second length of the distal section.